Publications Details

CBET-induced nonuniformity in direct-drive implosions on OMEGA [Slides]

Edgell, Dana H.; Colaitis, Arnaud; Guardalben, Mark J.; Kalb, Adam; Katz, Joe; Kwiatkowski, Joe; Mannion, Owen M.; Shvydky, Alex; Stoeckl, Christian; Turnbull, David; Froula, Dustin H.

Three dimensional polarization-dependent CBET plus beam balance and pointing are required to model nonuniformity in direct-drive implosions on OMEGA. Uniform laser energy absorption is essential for successful laser-direct-drive inertial confinement fusion but a growing body of evidence suggests OMEGA implosions are more asymmetric than predictions. By measuring the intensity and polarization of light scattered from individual beams, we have identified OMEGA’s polarization smoothing via distributed polarization rotators (DPR’s) as one previously unrealized source of nonuniformity. Polarization-dependent CBET along with beam energy balance, and beam pointing require three-dimensional modeling. Laser absorption mode 1 predictions from a fully three-dimensional CBET model correlate well with the observed direction of the core flow.